Apparatus for applying plastic coatings



July 31, w R BREND APPARATUS FOR APPLYING A PLASTIC COATING Filed Jan.14, 1942 2 Sheets-Sheet l mn "Hni' I H 53 FIG.3.

{i :33 s 6/ 21 23 22 I I 20 5:9 l3 ---26 INVENTOR. W/[Zl/IM A. DRE/VD'BY fi re- 1 ATTORNEY.

Patented July 31, 1945 OATINGS William R. Brend, East Orange, N. .L,assignor to Lock Joint Pipe Company, East Orange, N. 1., a corporationor New Jersey Application January 14, 1942, Serial No. 426,711

10 Claims.

This invention relates to apparatus for procementitious material withoutcausing segregation of the particles contained in the material andwithout otherwise upsetting r afiiecting the uniform consistency of thestream of material being projected.

Another object of the invention is to provide apparatus for projectingplastic mortar or concrete in a concentrated stream at a high velocityand to utilize these qualities of'the stream for obtaining a dense andstrong layer of mortar or concrete.

Another object of the invention is to provide an arrangement of rotarybrushes which reduces wear on brush bristles and at the same timeminimizes friction loss and thereby reduces the amount of power and costof brush replacement which had formerly been experienced in, the use ofrotary brushes to impel mortar or concrete.

Another object oi: the invention is to provide apparatus having brusheswhich are adjustable for projecting cementitious mixtures having a widerange of sizes of the contained particles of sand or stone and which arecapable of projecting difierent mixtures effectively and withoutappreciable variation in operating emciency.

A rotary brush impeller for projecting cementitious plastic material andwherein the ends 01' the bristles come into contact with a table orsteel plate, which together with the brush forms the discharge throat ofthe impeller, operates effectively enough as long as proper adjustmentis maintained, but in such apparatus there is a tendency for theefilclency to lower as the ends of the bristles and the table graduallywear away through abrasion and cause enlargement of the clearancethrough the throat. As a result frequent and costly replacements becomenecessary. The apparatus of the present invention obviates the use of atable and, in addition to bringing about a reduction 01' the cost ofoperation and a higher operating eiliclency, achieves less loss ofmaterial through diminution of side spray and provides a moreconcentrated stream by causing the'various particles constituting themass of mortar or concrete being projected to more nearly assume thesame velocity throughout any given cross-section of the projectedstream. 'A consequence of this is that a stronger and denser concrete isobtainable than when a single brush was used. The stream is moreconcentrated tor a given quantity of mateiral being projected and a highvelocity is possible with better coatings en- 8.

In addition to overcoming the above-mentioned shortcomings of a singlebrush machine, the present invention accomplishes further and otherobjects as will be set forth inv the accompanying specification andclaims and demonstrated by the drawings which show by way ofillustration, a preferred embodiment and the principle of the inventionand what is now considered the best mode for applying that principle.Other embodiments of the invention employing the same principle may beused and structural changes made as desired by those skilled in the art,within the spirit of the appended claims and without departing from thepresent invention.

In the drawings,

Fig. 1 is a section through an apparatus embodying the presentinvention;

Fig. 2 is a section through the discharge throat of the apparatusshowing the relationship of the rotary brushes and material received andprojected thereby;

Fig. 3 is an elevational view showing one set of side bearings for therotary brushes;

Fig. 4 is a section on line 4-4 of Fig. l; and

Fig. 5 illustrates a modified form or feeding mechanism for supplyingplastic material to the brushes.

In applying mortar or concrete, wear upon impelling mechanism isexperienced because of the granular character of the material beingprojected, the hardness of contained particles and the inertia of thematerial. The wear becomes greater when mortar containing coarse sand isprojected. The employment of larger aggregate, such as is used in manyforms of concrete, usually increases the wear proportionately. When arotary brush is used in conJunction with a sta tionary member or fixedconduit the velocity of the material in the stream varies from maximumnext to the brush, to minimum along the stationary member 'whichtogether with the brush constitutes practically the entire inside areaof a discharge orifice. Accordingly in such an arrangement the averagevelocity of the stream is relatively low and much power is wasted inscouring the stationary member with material. In accordance with thepresent invention these objections are obviated and advantages aregained.

'The present invention involves employment of a moving throat whichimparts high'veloclty to a stream of material while formingandaccurately controlling it. The drawings illustrate one manner oraccomplishing these results. The apparatus shown utilizes a pair-ofbrushes which rotate in opposite directions and which are so relatedthat their cylindrical-surfaces, as outlined by the ends of theirbristles, come into contact with the material being projected. The endsof the bristles form a roughened surface which takes hold of thematerial.

The brushes II and II are mounted upon parallel shafts l2 and II (Fig.2). The brushes are disposed to cooperate with each other so that theirperipheries provide material-impeding surfaces which move in the samedirection and at the same velocity. These two moving surfaces constitutea moving throat through, by and from which the material is projected.

Shaft i2 is mounted in a pair of bearings H, l and shaft I3 is mountedin a pair of bearings l6, I! (Fig. 4). These bearings are preferably sosupported as to permit adjustment of the shafts towards and away fromeach other.

Adjustability of the bearings is provided, particularly for enablingselection of the most desirable spacing between the peripheries of thetwo brushes toobtainthe best operating characteristic for the stream ofprojected material. In general, the projection of a mortar having finesand will be better accomplished by a fairly close spacing of the endsof the brush bristles sired spaced relation with respect to upperbearing block I5by a similarly constructed and of the two brushes at thelocus of discharge l8 and a slightly greater spacing is more desirablefor mortars containing coarser sand. For concrete mixtures containingaggregate in the form of gravel or broken stone, the spacing will beenlarged accordingly, but in all cases latitude is permissible to varythe quantity of flow.

Referring to Figs. 3 and 4, the upper and lower bearings for shafts i2and H3 at one side of the apparatus are supported in a rectangular framehaving a pair of standards 99, 20, connected together at their upper andlower ends. Each of these standards is provided with a guide rail H, 22,extending inwardly toward the shafts. The upper bearing block l5 has twopairs of ears 23, 24 (Fig. 3), one pair at each side, engaging each ofthe guide rails 2|, 22, respectively, the inside faces of a single pairof ears being. so spaced as to be in sliding contact with the sides ofits associated guide rail. Bearing block! I of shaft 13 is disposeddirectly beneath bearing block I5 and is similarly provided with pairsof ears 25, 26, at each side for engaging the respective guide rails 2|,22, by which they are guided.

Upper and lower bearing blocks H and it which support the ends of shaftsl2 and I3, respectively, adjacent the brushes, are similarly providedwith pairs of ears at their sides for engaging similar vertical guiderails 27, 28 (Figs. 1 and 4). These vertical guide rails are supportedby a pair of standards 29, 30, similar to standards i9, 20. The fourstandards are connected together into a rigid frame at their upper andlower ends.

The bearing blocks. and hence the shafts l2 and is supported thereby,are themselves supported by individual screw and nut units by which thespacing between the shafts can be changed.

The screw and nut unit supporting bearing l5,

for example, comprises a screw 3i engaged by a nut 32 which is supportedupon a cross-bar 33 connecting the upper ends of standards i9, 20. Thelower end of the screw has a mushroom head 31a which fits into a T-slot34 at the upper por-- tion of the bearing block. This connection permitsrotation of the screw with respect to the bearing block.

Lower bearing block I7 is maintained in a demounted adjusting screw 25which extends upwardly from member 38. As seen in Fig. 4 similar screwand nut-adjusting units are employed for maintaining the correct spacingbetween hearing blocks l4 and I5. Und'er.operating conditions thereaction of the'material passing between the brushes tends to causeseparation of the brushes and of'the shafts upon which they are mountedwith resulting tension in the adjusting screws. By adjusting the screwand nut units alignment and desired spacing of the shafts may beobtained.

The brushes may be of standard construction and have steel wire bristlesextending radially from a hub. It is preferable that these bristles beformed of tough metal, although vegetable bristles can be used. Brush I0is keyed to shaft l2 and brush II is keyed to shaft l3. The shafts aredriven by a'motor 31 (Fig. 1) through a chain connection 38 which passesover sprocket screws MI, 45 are provided on each side of the' bearingwhereby the bearing and idler may be laterally adjusted along sill 46which supports the bearing and adjusting screws.

The entire material-projecting assembly is mounted upon a carriage bywhich it may be moved along the surface to be covered. In the presentembodiment of the invention I have illusttated the rotary brushmechanism arranged for travelling along the outside of a pipe, but itcan be employed with a carriage which travels upon an arm extendingwithin a pipe for use in applying a lining or coating to the interiorwall.

The pip is rotated as the mechanism is guided or driven along itslength. The effect of the axial movement of the mechanism for applyingthe material and the rotation of the pipe is to cause the material totrace a helical path upon the outside of the pipe but it is-to beunderstood that the relative movement of the material-projectingmechanism and pipe is incidental only to the application of a continuouscoating and that the movements of either the pipe or of the applyingmechanism can be different from the arrangement specifically illustratedwithout affecting the results obtained, and that the mechanism may beused to apply layers of material' to planar .as well as curved surfaces.

In Fig. 1 the pipe 47 is suitably supported by trunnion rings 48, one ateach end of the pipe. Each trunnion ring rests upon a pair of rolls 48and 50. One of the rolls is driven by a motor 5|. The projectingmechanism is-mounted upon a carriage which travels on a pair of rails 52disposed alongside of the pipe. The carriage is driven by a motor 53which transmits motion to the axle 54 of the' carriage throughintervening gearing 55, variable speed transmission 55 and gears 51.

An important feature. of the present invention is its capability ofprojecting a substantially unifor stream of material wherein all of theparticles of material are moving at substantially the same velocity.This is because the material which is presented to the brushes andprojected from a locus midway between the axes of the brushes iscontacted above and below by propelling surfaces or projections whichhave a common linear velocity. This is particularly true when the endsof the bristles of the brushes pass quite close to each other.Substantially the same result is had when the spacing between thebrushes is increased because under such condition the particlesproximate the ends of the bristles impart their movement to particlesnearer the midpoint of the stream and the impelling force acts fromabove and below. The ends of the bristles constitute a moving orifice.

It is apparent that the thickness of the stream of material cannot bealtogether prevented from increasing as it moves beyond the brushes buteach particle of material disposed along a line 58, 59 throughout anygiven cross-section of the stream is moving at very nearly the samevelocity because all of the particles have a common initial velocityimparted to them by the combined action of the brushes. This combinedaction of the two brushes tends to concentrate the stream by minimizingdispersion after the material leaves the brushes and all of the materialis projected with equal effectiveness for forming a compact coating. Theavoidance of variation of the velocity of particles negatives anytendency to segregation between the coarser particles and the finerparticles and consequently the uniformity of the mixture is not variedby the impelling action.

It is desirable that the material be fed to the brushes at a uniformrate and without interruption. This feeding may be accomplished by theuse of screw element 80 which is contained within a round conduit 6|which opens directly against the brushes as shown in Fig. 2. The conduitflares at its discharge end to merge with and continue into the sidwalls 62, 63 and engage peripheral walls 64, 65 which enclose thebrushes. The connection with the four walls encasing the brushes issufiiciently tight to enable delivery of the material to the brushesunder pressure.

It is convenient to mount the screw element 60 and its containingconduit 6! at the lower portion of the hopper by which material issupplied to the conduit. A constant source of material will result in aconstant feed of material to th brushe which is efiected by powerrotation of the screw.

Inasmuch as a definite relationship exists be.-

tween the speed of the brushes and the feed of the material to thebrushes, there is advantage in driving the screw and the brushes fromthe same source of power. sprocket and chain connection 11, speedreducing transmission 18 and chain and sprocket connection 19 betweenthe transmission and. the motor 31. The employment of power feed for thematerial advancing to the brushes has particular advantage in that itenable the use of relatively dry mixes, and also assures a more uniformdelivery of material to the brushes and consequently This isaccomplished by a a flow of material from the brushes at uniformvelocity.

In Fig. 5 I have illustrated another form of mechanism for advancingmaterial to the brushes. In this embodiment of the invention thematerial contained in hopper is discharged from the lower end of thehopper onto a travelling conveyor 8| which directs the material alongthe conduit formed between the conveyor and the lower end 82 of thehopper. The conveyor is operated by power. The pull of gravity acts toprovide a constant supply of material to the rotating brushes 84, 85.

In order to assist the passage of material to the conveyor 8!,mechanical devices may be resorted to, such as, for example, a vibratorand motor 86 mounted on a wall of the lower portion of the hopper 80. Anagitator 81 having a plurality of. laterally-extending blades, whenrotated, will shred the material at the lower end of the hopper and caseits progress towards the conveyor. Brushes 84 and 85 are related to eachother and operate in the manner described with respect to brushes l0 andII.

The impelling brushes may assume the form of a pair of high speedendless belts, preferably carrying bristles on their exteriors, andarranged to pass a locus forming a discharge throat between them in themanner and form of the throat 18 between the two rotary brushes shown inFig. 2.

What is claimed is:

1. In apparatus for applying a plastic coating, the combinationcomprising a pair of oppositely positioned driven elements for impellingplastic material from therebetween, said driven elements having likemeans defining their peripheries for engaging and impelling plasticcementitious material containing discrete particles, means for directinflow of plastic material simultaneously to approaching material-engagingportions of both of said peripheries, means supporting said drivenelements so as to present recurring D0 tions of their peripheries toplastic material directed thereto, and means for actuating said drivenelements and material-engaging means thereon at the same speed to impelthe plastic material directed thereto in a constant stream.

2. In apparatus for applying a plastic coating, the combinationcomprising a pair of driven elements for impelling plastic material,means on the surfaces of said driven elements for engaging plasticcementitious material containing discrete particles for impartin motionthereto, means for mounting said driven elements opposite each other sothat the motion-imparting surfaces thereon can be moved in the samedirection at their positions of closest approach to each other, meansfor directing plastic material simultaneously to approaching portions ofboth of the motion-imparting surfaces carried by said driven elements,means for simultaneously driving said driven elements to cause them toproject a stream of plastic material from between their motionimpartingsurfaces, and means for adjusting said driven elements to change thedimension of their closest approach.

3. In apparatus for applying a plastic coating, the combinationcomprising a pair of rotary elements for impelling plastic material,bristles carried by said rotary elements and extending substantiallyradially thereof, means for mounting said rotary elements opposite eachother on parallel axes so that the bristles of one of said rotaryelements and the bristles of the other of said rotary elements can passa given locus between the rotary elements without touching each other,

means for directing plastic material to said locusbetween the rotaryelements, and means for driving said rotary elements in oppositedirections so as to cause them to project a stream of plastic materialfrom therebetween.

4. In apparatus for applying a plastic coating,

the combination comprising a pair of cylindrical brushes, each of saidcylindrical brushes having bristles projecting outwardly from the axisof rotation of the cylindrical brush, means for mounting saidcylindrical brushes opposite each other on parallel axes, said meansbeing spaced sufliciently apart to provide a locus for the discharge ofmaterial from between the brushes, means for supplying plastic materialto the locus between the brushes, and means for driving said brushes inopposite directions to project plastic material from said locus betweenthe brushes.

5. In apparatus for applying a plastic coating, the combinationcomprising a pair of cylindrical brushes, each of said cylindricalbrushes having bristles projecting away from the axis of rotation of thebrush, means for mounting said cylindrical brushes opposite each otheron parallel axes so that the bristles of one of said cylindrical brushesand the bristles of the other of said cylindrical brushes can pass agiven locus between the cylindrical brushes when they are rotated, meansfor adjusting the separation of the peripheries of said cylindricalbrushe at said given locus, means for supplying plastic material to thelocus between said rotary brushes, and means for driving saidcylindrical brushes in opposite directions to cause the bristles carriedby the cylindrical brushes to pick up plastic material and project itfrom said given locus,

6. In apparatus for applying a plastic coating, the combinationcomprising a pair of rotary elements, each having bristle-likeperipheral surfaces, means mounting said rotary elements so as toprovide a discharge throat between the bristle-like peripheral surfacesof the rotar elements, means for driving said rotary elements so as toprovide between them continually changing bristle-like surfaces at saiddischarge throat, and means for applying plastic material to saiddischarge throat between the adjacent rotary elements.

7. In apparatus for applying a plastic coating, the combinationcomprising a pair of rotary elements, each having bristle-likeperipheral surfaces. means mounting said rotary'elements so as toprovide a discharge throat between the bristleiike peripheral surfacesof the rotary elements, means for driving said rotary elements so as toprovide between them continually changing bristle-like surfaces at saiddischa ge throat, conduit means for directing plastic material to saiddischarge throat between the adjacent rotary elements, and means forforcibly advancing plastic -material through said conduit means and intosaid discharge throat.

8. In apparatus for applying a plastic coating, the combinationcomprising means including a pair of driven elements cooperativelyarranged to present moving surfaces for impellin'g plastic material frombetween said surfaces, means mounting said driven elements with portionsof said moving surfaces opposite each other so as to present a fixedlocus through which the moving surfaces of said driven elements pass andform a throat for the passage of plastic material coming into contactwith and between the moving surfaces, conduit means for conveying D a Cterial to the throat at said locus, means for forcibly advancing plasticmaterial through said conduit means and against approaching portions ofboth of the moving surfaces of said plastic material-impelling elements,and means for driving said plastic material-impelling elements to causetheir moving surfaces to pick up and project plastic material advancedthereagainst'and project the same in a stream.

9. In apparatus for applying plastic material, the combinationcomprising a pair of cylindrical brushes having substantially continuousouter surfaces, means supporting said brushes with portions of theircylindrical surfaces opposite each other so as to provide a dischargethroat with the surfaces of said brushes forming opposite walls of thedischarge throat, a conduit having a discharge end for supplying plasticmaterial to the ingress portion of said throat, means for feedingplastic material through said conduit under pressure, and means forsimultaneously actuating said feeding means and said brushes for causingconstant delivery of a stream of plastic material from said throat.

10. In apparatus for applying plastic material, the combinationcomprising a discharge throat having oppositely disposed surfaces havingprojections for gripping plastic cementitious material containingdiscrete particles, means supporting said discharge throat with portionsof its materialgripping surf-aces opposite each other, means for drivingsaid surfaces in the same direction at said throat, a conduit having adischarge end for supplying plastic material to the ingress portion ofsaid throat, means in said conduit for exerting pressure on plasticmaterial contained in said conduit for forcibly advancing the same ontosaid plastic material-gripping surfaces of the ingress portion of saidthroat, and means for simultaneously operating said driving means andsaid pressure exerting means to cause the projection of plastic materialfrom said throat.

WILLIAM R. BREND.

